1. Field of the Invention
The present invention relates to an image taking apparatus equipped with a plural number of IC tags.
2. Description of the Related Art
In the field of physical distribution management, instead of a bar code label stuck on a commodity, an IC tag by which information transmission through radio communication is possible (which is also called a wireless tag) has become used. As an application of the IC tag, a technology of acquiring information of a photographic subject from an IC tag held by the subject by using a digital camera has been proposed.
On the other hand, IC tags are divided into one type that has not an internal power supply in the IC tag but transmits information memorized in the IC tag by using the energy of the radio wave sent from an external reader/writer (this type is called the passive type hereafter), and another type that has an internal power supply in the IC tag and can actively transmit information memorized in the IC tag (this type is called the active type hereafter).
The passive type IC tag has an advantage in that it can communicate if the power supply of an apparatus having the IC tag malfunctions (when a battery is not loaded, for example), or even if the apparatus is broken. On the contrary, the passive type IC tag has disadvantages in that it generally provides a short communication distance and has a small data capacity to be memorized. Although the active type IC tag has advantages, as compared to the passive type IC tag, in that its communication distance is long and has a large data capacity to be memorized, it is expensive.
Since the active and passive type IC tags having mutually different characteristics have merits and demerits, respectively, it may be reasonable to use both types together in order to utilize advantages of them. However, if both type IC tags are merely used together, a problem may arise that interference occurs by both type IC tags responded to the radio wave from the reader, so that the reader side cannot receive correct information from the IC tags.